help on the time diffrence between the client and server

hello folks.we operate a activedirectory on 2003 functional level running on server 2008r2.the client machines run win 7 pro.some users have been complaining of this error message above and after runing dcdiag /test:netlogons, i get 'LsaPolicy operation failed with error 53 The network path was not found.'.secondly i ran the comand @NET TIME /DOMAIN: /SET. on one of the machines, which ran successfuly but unfortunately the error message'time diffrence between the client and server failed' still persisits.any recommended solution is deeply appreciated.